Field of the Invention
The present invention relates to a wiring board having a through hole and a manufacturing method thereof.
Description of the Related Art
A wiring board consists of a fiber reinforced resin plate made of reinforcement fiber such as glass fiber and matrix resin. When a terminal, which is pressed and connected, is pressed in a through hole penetrating through the wiring board, a portion near the through hole of the wiring board whitens.
In this manner, the wiring board in which the whitening is generated is judged as inferior products. As a result, the productivity of the wiring board is reduced. Further, when a test of high temperatures and humidity is performed in the wiring board including the whitening, insulation properties result in low result and it becomes a problem.
In Patent Document 1, a technique relaxing physical stress when pressing a terminal in a through hole by changing a shape of the terminal is disclosed.
More specifically, as shown in FIG. 7, a press-fit terminal 9′ including a press-fit portion having a noncontact dent 9d′ is used in the Patent Document 1. As a result, a deformation of the through hole 7 and a cleave deformation of a buried resin portion can be prevented by elastic restoring force of the press-fit portion.
However, although using this technique, generation of the whitening in a portion around the through hole of the wiring board has not been able to prevent completely.
[Patent Document 1] JP, A, No. 2009-21016